Tandy 1000 MS-DOS Reference Manual page 78

"
Chapter 6 / Command Reference
CTTY (Change I/O Device)
CTTY device
Internal
Changes the input/output (I/O) device to the device specified.
Normally, input comes from the keyboard and output goes to the
screen.
Parameters
device
is a device which can be either of the following:
AUX - specifies an auxiliary device, normally the RS-232
serial port.
COMI or COM2 - specifies RS-232 serial Port 1 or Port 2.
CON - specifies the console (input from the keyboard and
output to the screen).
Any other character-oriented device capable of both input and
output.
Notes and Suggestions
• Because the printer is not capable of input, PRN is not a valid
CTTY device.
• CTTY affects only programs that are MS-DOS function calls.
Other programs, such as BASIC, ignore the CTTY command.
Examples
c
tty
a u x
I
ENTER
I
moves all command input/output (I/O) from the current device to
the auxiliary device.
c
tty
con
I
ENTER
I
changes the input device to the keyboard and the output device
to the screen.
64
i
i